{"instruction": "You are an expert in named entity recognition. Please extract entities that match the schema definition from the input. Return an empty list if the entity type does not exist. Please respond in the format of a JSON string.", "schema": ["manufacturing standard", "enabling technology", "engineering feature", "concept or principle", "process parameter", "material"], "input": "The final hardness values vary from about 220 to 280 HV2 ; the yield stress and tensile strength are 520 and 790 MPa , respectively , and a toughness of about 50 J is obtained at room temperature ."}
{"manufacturing standard": [], "enabling technology": [], "engineering feature": [], "concept or principle": ["MPa"], "process parameter": ["temperature"], "material": []}